This project is concerned with developmental aspects of cross-language speech perception. The studies proposed are designed to increase our understanding of the role of age as well as cultural and sensory experience in linguistic perceptual development. Attention is to be paid to the practical question of maintaining or, recovering broad perceptual abilities to aid in learning second languages. In part, the basis of this emphasis arises out of consideration of research showing a relationship between early multilanguage exposure and subsequent acceleration in perceptual/cognitive flexibility and acquisition of accent-free second language. The results of preliminary work of ours suggests that infants discriminate speech sounds according to phonemic categories without prior specific language experience, whereas adults may lose this ability as a function of either age and/or language experience. Further, our preliminary research suggested that recovery of this early phonemic-based flexibility is difficult and may impede the second language acquisition process. To explore these and related questions we have developed a three-part program of study utilizing a variate of the visually reinforced infant speech discrimination (VRISD) paradigm. In the first part, we plan to test the generalizability of our original findings in regard to infant vs. adult discrimination by examining discrimination of Nootkan (an American Indian language) speech contrasts. The second part is designed to help elucidate the developmental progression of this apparent "decline" (and the possibility of recovery) in non-native speech discrimination abilities as it relates to age and level of cognitive functioning. In the third part, we plan to look directly at the effect of age of exposure on both maintaining and recovering perceptual flexibility. In this endeavor, we will examine speech discrimination in three subgroups of Nootkan Indians who were first exposed to and/or learned English at different ages.